Toyota CH-R Service Manual: Key Reminder Buzzer does not Sound

DESCRIPTION

The key reminder warning buzzer sounds when the driver door is opened while the ignition switch is off or ACC. The key reminder warning buzzer is activated when the main body ECU (multiplex network body ECU) sends an unlock warning switch signal and driver door courtesy light switch signal to the combination meter assembly via CAN communication.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

PROCEDURE

1.	CHECK COMBINATION METER ASSEMBLY (BUZZER OPERATION)

(a) Turn the ignition switch to ON. Place luggage on the front passenger seat to cause the seat belt warning light to blink.

(b) When driving the vehicle at 20 km/h (12 mph) or higher, check that the seat belt warning buzzer sounds to inform that the front passenger seat belt is not fastened.

HINT:

The key reminder warning system sounds the buzzer built into the combination meter assembly as a key reminder warning. This buzzer is also used for the seat belt warning system. Therefore, check the operation of the combination meter buzzer by checking if the buzzer sounds to inform that the seat belt is not fastened.

OK:

Combination meter buzzer sounds.

NG

REPLACE COMBINATION METER ASSEMBLY

OK

2.	READ VALUE USING TECHSTREAM (FL Door Courtesy SW)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Main Body / Data List.

(e) Read the Data List according to the display on the Techstream.

Body Electrical > Main Body > Data List

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
FL Door Courtesy SW	Front door courtesy light switch assembly LH signal	OFF or ON	OFF: Front door LH closed ON: Front door LH open	-

Body Electrical > Main Body > Data List

Tester Display
FL Door Courtesy SW

OK:

The Techstream indicates ON or OFF according to the driver door conditions shown in the table.

NG

GO TO STEP 7

OK

3.	READ VALUE USING TECHSTREAM (Key Unlock Warning SW)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Main Body / Data List.

(e) Read the Data List according to the display on the Techstream.

Body Electrical > Main Body > Data List

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
Key Unlock Warning SW	Unlock warning switch signal	OFF or ON	OFF: No key in ignition key cylinder ON: Key in ignition key cylinder	-

Body Electrical > Main Body > Data List

Tester Display
Key Unlock Warning SW

OK:

The Techstream indicates ON or OFF according to whether the key is in the ignition key cylinder.

OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

NG

4.	INSPECT UNLOCK WARNING SWITCH ASSEMBLY

(a) Remove the unlock warning switch assembly.

Click here

(b) Inspect the unlock warning switch assembly.

Click here

NG

REPLACE UNLOCK WARNING SWITCH ASSEMBLY

OK

5.	CHECK HARNESS AND CONNECTOR (UNLOCK WARNING SWITCH ASSEMBLY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

(a) Disconnect the F13 unlock warning switch assembly connector.

(b) Disconnect the 3A instrument panel junction block assembly connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
F13-1 (UN+) - 3A-41	Always	Below 1 Ω
F13-2 (UN-) - Body ground	Always	Below 1 Ω
F13-1 (UN+) or 3A-41 - Body ground	Always	10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

6.	INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

(a) Remove the instrument panel junction block assembly.

Click here

*a

Component without harness connected (Instrument Panel Junction Block Assembly)

-

-

(b) Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
3A-41 - MB-3 (KSW)	Always	Below 1 Ω

OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

NG

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

7.	INSPECT FRONT DOOR COURTESY LIGHT SWITCH ASSEMBLY LH

(a) Remove the front door courtesy light switch assembly LH.

Click here

(b) Inspect the front door courtesy light switch assembly LH.

Click here

NG

REPLACE FRONT DOOR COURTESY LIGHT SWITCH ASSEMBLY LH

OK

8.	CHECK HARNESS AND CONNECTOR (FRONT DOOR COURTESY LIGHT SWITCH ASSEMBLY LH - MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU))

(a) Disconnect the M11 front door courtesy light switch assembly LH connector.

(b) Disconnect the F15 main body ECU (multiplex network body ECU) connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
M11-1 - F15-6 (FLCY)	Always	Below 1 Ω
M11-1 or F15-6 (FLCY) - Body ground	Always	10 kΩ or higher

OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR